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If the sum of the first n positive integers is S, what is the sum of t
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10 Jun 2022, 03:00
10 Jun 2022, 03:00
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53% (01:19) correct
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If the sum of the first n positive integers is S, what is the sum of the first n positive even integers, in terms of S ?
(A) S/2
(B) S
(C) 2S
(D) 2S + 2
(E) 4S
(A) S/2
(B) S
(C) 2S
(D) 2S + 2
(E) 4S
Part of the project: GRE QCQ & PS 3 Questions Every One DAILY Challenge - (2022)
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GRE Math Essentials for a TOP Quant Score - Q170!!! (2021)
GRE Geometry Formulas for a Q170
GRE - Math Book
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
GRE Math Essentials for a TOP Quant Score - Q170!!! (2021)
GRE Geometry Formulas for a Q170
GRE - Math Book
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Re: If the sum of the first n positive integers is S, what is the sum of t
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10 Jun 2022, 05:28
10 Jun 2022, 05:28
1
Carcass wrote:
If the sum of the first n positive integers is S, what is the sum of the first n positive even integers, in terms of S ?
(A) S/2
(B) S
(C) 2S
(D) 2S + 2
(E) 4S
(A) S/2
(B) S
(C) 2S
(D) 2S + 2
(E) 4S
Given: The sum of the first n positive integers is S
So, we can write: S = 1 + 2 + 3 + 4 + . . . + n
Question: What is the sum of the first n positive even integers, in terms of S ?
Let E = the sum of the first n positive even integers
So, we can write: E = 2 + 4 + 6 + 8 + . . . + 2n
Factor out 2 to get: E = 2(1 + 2 + 3 + 4 + . . . + n)
Since S = 1 + 2 + 3 + 4 + . . . + n, we can substitute to get: E = 2(S)
Answer: C
Re: If the sum of the first n positive integers is S, what is the sum of t
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11 Jun 2022, 00:04
11 Jun 2022, 00:04
1
If we assume that S is any set of consecutive positive integers, then naturally, multiplying the set by 2 will give us a set of all that positive integers.
S = {1, 2, 3}
2S= {2, 4, 6}
One may experiment with other choices on a small set-frame.
The answer is (C)
S = {1, 2, 3}
2S= {2, 4, 6}
One may experiment with other choices on a small set-frame.
The answer is (C)
